Commitments and Contingencies (Details Textual) - 6 months ended Jun. 30, 2019 $ in Millions, $ in Billions	USD ($)	CAD ($)
Loss Contingency Accrual	$ 22.0
Commitments and Contingencies (Textual) [Abstract]
Site contingency number of sites checked	6	6
Sites in various stages of follow-up	4
Sites with limited soil and ground water impact	2
Sites requiring additional investigation	2
Minimum [Member]
Commitments and Contingencies (Textual) [Abstract]
Notice required to cancel purchase agreements, days	30 days	30 days
Maximum [Member]
Commitments and Contingencies (Textual) [Abstract]
Notice required to cancel purchase agreements, days	120 days	120 days
U.S. Liquids [Member]
Commitments and Contingencies (Textual) [Abstract]
Site contingency number of sites checked	5	5
U.S. Gas [Member]
Commitments and Contingencies (Textual) [Abstract]
Site contingency number of sites checked	1	1
Canada [Member]
Commitments and Contingencies (Textual) [Abstract]
Asset retirement obligation liability	$ 25.8
Estimated cost to retire facilities	$ 141.7
SemCAMS Midstream [Member]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%
Keyera Pipeline Project [Domain]
Estimated Project Costs	$ 992.7	$ 1.3
Interest In Joint Venture	50.00%	50.00%